Sleep Calculator
Suggest wake or sleep times based on 90-minute sleep cycles.
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Frequently asked questions
A typical adult sleep cycle is roughly 90 minutes through light, deep, and REM stages. Waking near the end of a cycle tends to feel less groggy than waking mid-cycle. This is a rule of thumb, not a medical guarantee.
The number of minutes you usually spend in bed before actually falling asleep. The calculator subtracts (wake mode) or adds (sleep mode) this buffer so the cycle count starts from when you are likely asleep.
No. It is a rough planning tool. For ongoing sleep problems, talk to a qualified clinician.
Last updated 2026-06-03.